/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */


package org.graalvm.compiler.phases.common;

import org.graalvm.compiler.core.common.type.ObjectStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ParameterNode;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.phases.Phase;

/**
 * Modifies the stamp of all object {@linkplain ParameterNode parameters} in a graph to denote they
 * are non-null. This can be used for graphs where the caller null checks all arguments.
 */
public class NonNullParametersPhase extends Phase {

    @Override
    protected void run(StructuredGraph graph) {
        Stamp nonNull = StampFactory.objectNonNull();
        for (ParameterNode param : graph.getNodes(ParameterNode.TYPE)) {
            if (param.stamp(NodeView.DEFAULT) instanceof ObjectStamp) {
                ObjectStamp paramStamp = (ObjectStamp) param.stamp(NodeView.DEFAULT);
                param.setStamp(paramStamp.join(nonNull));
            }
        }
    }
}
